1. Field of the Invention
The present disclosure relates to a recording-element substrate of a liquid ejection apparatus typified by an inkjet recording apparatus.
2. Description of the Related Art
Higher-quality higher-durability (long life) liquid ejection apparatuses are required.
Japanese Patent Laid-Open No. 55-132259 discloses a recording head that provides a high-quality image. This recording head has a plurality of heaters in each of channels communicating with ejection ports. The heaters are configured to be able to supply pulse signals individually. By controlling the supply timing of pulse signals to the heaters, the size of droplets ejected from the ejection ports is adjusted. By adjusting the size of the droplets, an image at high gray level is provided.
Japanese Patent Laid-Open No. 2010-42629 discloses a liquid ejection apparatus that provides a high-quality image. This liquid ejection apparatus has a pair of heating elements in each liquid chamber. The liquid chamber communicates with one nozzle. The heating elements are opposed to the nozzle.
If pulsed currents with the same value are supplied to the heating elements, liquid is ejected in a first direction from the nozzle. If pulsed currents with different values are supplied to the individual heating elements, liquid is ejected in a second direction different from the first direction. Controlling the ejecting direction with pulsed current values allows adjustment of droplet landing positions, thus allowing providing a high-quality image.
Japanese Patent Laid-Open No. 63-191644 discloses an inkjet recording apparatus that has achieved high durability. This inkjet recording apparatus has a plurality of heater units for one ejection port. The heater units are connected to a pair of electrode in parallel. The heater units heat liquid to generate bubbles, so that the liquid is ejected from the ejection port.
It is known that a heater is damaged due to pressure fluctuations, a so-called cavitation impact, caused due to a series of processes, that is, generation, growth, and shrinkage of bubbles. With the inkjet recording apparatus disclosed in Japanese Patent Laid-Open No. 63-191644, even if part of the heater units is damaged due to a cavitation impact, liquid can be ejected using the other heater units. Thus, the high durability of the heaters is achieved.